The present invention relates to a pin for holding and/or cooling of ceramic coatings in hot reaction chambers, particularly to a pin which is composed of two components. The invention also relates to a method of manufacturing of such pin.
A pin for holding and/or cooling the ceramic coating in hot reaction chambers and composed of two components is disclosed in U.S. patent application Ser. No. 572,922. More particularly, this pin includes a pin shaft composed of a material which under the respective reaction conditions in the hot reaction chamber is temperature-, corrosion-, erosion- and oxidation-resistant. It further includes a pin cap which is composed, to the contrary, of a material corresponding to the material of the wall of the hot reaction chamber. The pin shaft is fitted in the pin cap and connected with the latter in a firm and heat-conductive manner.
In hot reaction chambers, such as for example in firing chambers or reaction chambers of coal gasifiers, high temperatures prevail which are required for the course of the desired reactions and/or for a liquid slag withdrawal. As a rule it is necessary here to provide the walls of the hot reaction chambers with a respective temperature-resistant ceramic coating. This coating which is normally formed as a ramming or spraying mass is applied on the walls of the hot reaction chambers and serves for protecting these walls from damage by the action of the high temperature and at the same time for providing the required heat insulation in the hot reaction chamber so as to reliably maintain the desired high reaction temperatures inside the chamber. The walls of the hot reaction chambers can be naturally so-called tubular walls, when for example the hot reaction chamber is a melting chamber of a vaporizer or a reaction chamber of a coal pressure gasifier. For holding and/or cooling the ceramic coating, the walls of the hot reaction chamber are normally provided with pins on which the ceramic coating is mounted. Approximately 2000 pins are used per square meter of the coating.
The pin described in the above-mentioned patent application serves this purpose and is sufficient in the sense that, on the one hand, it has a high temperature-, corrosion-, erosion- and oxidation-resistance and, on the other hand, can be welded in a lasting manner to the wall of the hot reaction chamber without inflicting a damage to the wall material. Moreover, this pin can be produced in a relatively simple and cost-economical manner. For the connection of the pin shaft with the pin cap, various processes are proposed in the above-mentioned patent application, namely shrinking-on, resistance welding, screwing and cementing.